TOp 10 moves for thinner thighs: For best results, perform 15 reps of each move, back to back without rest, up to four days a week. And be sure to couple your lower-body workouts with cardio exercise and a healthy diet to stay slim and trim for good. Want to boost your burn? Try adding a set of 5-10 pound dumbbells to some of the strength moves for more of a challenge.